Ever since 1970 the search has been going on for a solution to what the International Telecommunications Union called the Integrated Services Digital Network or “ISDN”, a new system, a development of the analogue or digital public switched telephone network to a single common network infrastructure in order to offer voice, data and multimedia services by way of a single interface. The work carried out by the International Consultative Committee for Telephony and Telegraphy (CCITT) gave rise to a set of Recommendations for the ISDN system, but they did not finally achieve the desired result, as the resultant network used low speed circuit technology (64000 bits per second), which was not suitable for data traffic. Subsequently, numerous attempts have been made in this respect, such as ATM, or the more recent ones based on the use of ADSL techniques, without the objective of total service integration being achieved so far.
Recently, new proposals have appeared for the integrated network, with different orientations. Some propose maintaining the classic infrastructure of digital telephone circuits, adding XDSL type accesses, fundamentally with the ADSL alternative, providing access to the Internet and IP services on an ATM switch infrastructure. This may not really be considered as an integrated network as, although all the communications are digital, the telephony goes on using the circuits technique, while the data are carried on packet networks, there actually being three network technologies: pure circuits for the telephone, virtual circuits for ATM and datagrams for IP. Another very serious problem of ATM technology is that it is based on virtual circuits (connected mode), while IP and Ethernet are based on datagrams (non-connected mode). A universal service like that proposed in this invention would not be possible with ATM, as has already been adequately shown with all the attempts that have been made since 1993 to offer local network services with ATM, being particularly illustrative what happened with LANE (LAN Emulation).
Furthermore, systems are appearing that offer access to the telecommunications network based on Ethernet technology—IEEE 802.3, but only as a connectivity service between different points of connection to the network. The typification of the Metro Ethernet Forum is illustrative of these.
The IEEE 802.3 Ethernet Standardisation Committee has set up the IEEE 802.3ah (Media Access Control Parameters, Physical Layers and Management Parameters for subscriber access networks) working group for access to telecommunications networks based on Ethernet. This standard is of use as a base for the development of the invention being described here, as it provides the basic specifications for setting up connections with a telecommunications network over the telephone pair, a key element for taking advantage of the existing infrastructure. With 1200 million telephone lines in the world, according to a recent estimation published by Lucent Technologies, there is an enormous potential for an integrated services solution capable of using the traditional telephone access loop infrastructure.
This invention corresponds to a universal telecommunications service based on Ethernet technology, according to the specifications of the IEEE 802.3 and ISO/IEC 8802-3 standards to which there will be applied the acronym “UETS” (Universal Ethernet Telecommunications Service), which refers to the equipment and services needed for the evolution, development and implementation of a universal network of services integrated on a single interface based on the packet technique in non-connected mode, using as the logic means data exchange the formats defined in standards IEEE Std 802.3 and IEEE Std 802.2 [ISO/IEC 8802-2] and as the physical means the access infrastructure over copper pairs of the analogue or digital telephone network, the electrical network with PLC (Power Line Communications) techniques, optical fibers and wireless systems.
Standard IEEE Std 802-2001 defines the term “local area network” or LAN as a “computer network, located on a user's premises, within a limited geographical area”. It also defines “802 LAN” as “a LAN consisting of an access domain using either a MAC protocol specified in one of the IEEE 802.n and ISO/IEC 8802-n Standards”. This is applicable to IEEE 802.3 and ISO/IEC 8802-3, from where this invention takes the “Ethernet domain” concept.
The object of the invention is a new universal digital telecommunications service, where a clear distinction is made between the “Ethernet domain”, in which the service is offered, and the “IP domain”, which offers connectivity via the Internet, with the possibility of either versions 4 and 6 of the IP Internet protocol being used. One of its advantages is that it allows existing telephone pairs to be used for connecting the special Ethernet network termination devices, described in this invention, with the network resources situated in the services supplier's part. For the connection data pairs, optical fibers, wireless systems or the ones based on the electrical network like PLC (Power Line Communications) may be used, when the service or broadband needs advise it.
This invention takes advantage of the experience gained by the more mature technologies: the classic physical circuit telephone network, the virtual circuit networks (X.25, Frame Relay and ATM), the Ethernet-based local area networks, and the Internet, now used all over the world. By choosing the best of all these and combining it in an absolutely novel way, an end solution has been reached that is extraordinarily simple in its approach, efficient in its working, austere in the use of resources, environmentally friendly due to consuming the strictly necessary energy by means of the power control mechanism, and of assured operation through using well proven techniques and those in which the inventor has long practical experience. The network proposed is capable of offering all the advanced telecommunications services: voice, telephony, data, videoconference, image, real-time video, on-demand video, remote control, remote metering, network storage services, access to applications servers, transactional services, network games, tele-education, telemedicine, e-business, etc.
Ethernet-based local area networks are used today all over the world and form an unparalleled data system, hitherto confined to building and campus installations. Their advantages are evident and their wide-scale use has brought about a reduction in the costs of the network equipment, now very largely composed of switches to which the terminals are connected at speeds of 10, 100 and 1000 megabits per second. A key idea of this invention is the extension of the Ethernet local network to the telecommunications installations of the operator, who in this way is able to offer services equivalent to those currently offered in local building or campus networks, being systems of proven efficacy and of which there is a great deal of experience, so that it is possible to offer advanced high-speed services at a minimal cost per bit transmitted.
In order to be able to transport voice, data and video at the same time over Ethernet links, at least 2 megabits per second in balanced duplex mode is required, i.e. at the same speed in both transmission directions. Thus, the requirements of the International Telecommunications Union are also met, as in Recommendation I.113 of the ITU Standardisation Sector broadband is defined as a “faster transmission capacity than the primary speed of the Integrated Services Digital Network (ISDN) at 2.0 megabits per second”, which represents a net speed of 1.92 megabits per second, as the ISDN primaries transport 30 channels at 64000 bits per second each. Although a minimum service is assured with that speed, it is desirable to raise it to 10 or 100 megabits per second whenever possible.
Furthermore, in order to be considered a genuine Telecommunications Service, the connection must meet certain particular conditions, taken from the classic telephone network, such as the terminal power supply via the pairs so as to guarantee the emergency call service (112 in Europe or 911 in the United States), and the terminal power control so as not to consume energy from the exchange other than when essential (the current Ethernet network devices consume energy all the time). Supposing that this were used for access to broadband networks and applying the most conservative forecasts of 200 million users in 2010, the minimum energy saving would be in the region of 14 TWh a year, equivalent to some 1400 million euros a year at the current price of electric energy.
The 2BASE-TL and 10PASS-TS modalities of the new IEEE 802.3ah standard make it possible to access the telecommunications network at 2 and 10 megabits per second over a single telephone pair, including the procedures necessary for the link operation and maintenance (OAM). To have the functions required by this invention available, it is necessary to add the functionalities that are not in the afore-mentioned IEEE 802.3ah standard: power supply over the telephone pair, power control and management for energy saving and increasing the speed up to 100 megabits per second. Power supply over the pair does not represent a problem, as this is done at the ISDN connections and when the ADSL router co-exists in the same telephone pair with the DC-powered telephone. The power control is included in the IEEE 802.11 systems, as described in point 11.2 of the standard (Power Management), it being possible to adapt this system to transmission over pairs or to use other techniques, such as those defined for ISDN systems. Chips already exist for operation at 100 megabits per second over telephone pairs, such as those made by Fujitsu Access Ltd.
The power source in the access equipment, located on the user's premises, would mean that, in the event of a power failure, the connection would be lost, which is not acceptable in a true Telecommunications Service, in which it is necessary to maintain emergency communications. In addition, power supply from the exchange is more efficient from the energy point of view than local supply, more reliable through being able to incorporate a higher level of redundancy, and to assure the service batteries are incorporated in the exchange—a classic telephone network solution.
In order to offer the basic telephone service and guarantee the emergency call service, the user's end network terminator will be supplied from the exchange and will include a telephone that may use the voice on packets (VoP) techniques with SIP (Session Initiation Protocol) signalling, according to the specifications of the corresponding IETF (Internet Engineering Task Force) RFCs. As an alternative, it would also be possible (though not recommendable) to make use of Recommendation H.323 and related International Telecommunications Union ones. The access service to the telephone network can be offered and managed by the own operator, thereby permitting the telephone number to be maintained both for incoming and outgoing calls. It would also be possible to assign a specific prefix for the data terminals wishing access to and from the telephone network, such as 050 in the case of Japan, or to use ENUM type techniques.
The Internet model resolves the concepts universal network and terminal services, with the TCP and IP protocols for interconnection, and the Internet applications use a universal presentation based fundamentally on the browser model (Netscape, Internet Explorer, etc.) and on the W3C specifications. The applications, for communicating over the Internet, set up connections by the association of IP addresses and IP and TCP/UDP source and destination ports. The information travels in circuit mode with TCP or in datagrams mode with UDP on the IP datagrams. The main problem of the TCP/IP protocol stack is that they correspond to layers 3 and 4 of the reference communications architecture, and they correspond to software applications, which represents a major limitation as regards efficiency, both in the hosts and in the routers. If we take as a reference the strategy used in the virtual circuit networks, we may see that when the layer 3X.25 protocol made it impossible technically speaking to increase the speed of the network connections, a change was made to layer 2 switching with Frame Relay. In the case of the Internet, it would be fundamental to adapt the applications so that instead of the IP protocol they should directly use MAC 802.3 encapsulating, which with its 6 octets of addresses has 140,737,488,355,328 possible different combinations (in local networks, with the ARP process, an IP address is associated with a MAC address). While the IP datagrams have to progress by routing procedures, the MAC 802.3 frames use very mature switching procedures proven in the field of local networks. When wishing to extend the Ethernet domain to remote premises, pure circuit techniques may be used with synchronous digital hierarchy (SDH) or MPLS tunnels, which transport the MAC 802.3 frames directly. At transport layer, the TCP protocol could be substituted for internal connections in the Ethernet domain by the LLC 802.2 type 2 protocol for setting up reliable circuits and the UDP protocol by the LLC 802.2 type 1 or type 3, in accordance with the needs of the applications. For this purpose, for instance, a LSAP value not used currently could be employed for indicating that the two octets corresponding to the TCP or UDP are going next, in the MAC field local address could be used, indicated with the U/L bit fixed to 1, and transport the IP addresses in the source and destination MAC addresses field. In this way, use could be made of all the current Internet applications that go on TCP, UDP and IP within the Ethernet domain.
The set of network elements that uses the MAC/IEEE 802.3 and LLC/IEEE 802.2 link layer protocols for the connections of network users and servers constitutes the “Ethernet domain”, this being limited to the infrastructure of the services supplier and isolated from other environments, in particular from the Internet IP domain. The services may be offered in the Ethernet domain, in the IP domain or by a combination of both. The owner operator of the physical network infrastructure, which connects the users with the switching exchange, may use various techniques to route the traffic to multiple suppliers of services, for example by means of VLAN techniques according to the IEEE 802.1 standard or by the use of local MAC addresses identifying every one of the suppliers. With this solution, the suppliers may offer services in the Ethernet domain both with LLC/MAC and with TCP/IP transport, in the latter case taking advantage of all the current Internet environment equipment and applications.
Another important element of the invention is the intelligent terminal, in which all the common Internet applications run on a supervisor capable of being connected to the Ethernet domain by means of the protocols described above (LLC/MAC and TCP/IP) and communicating in it with the servers, which will also have the corresponding connectivity protocols. The terminals, both clients and servers, will have TCP/IP protocol stacks for connectivity with the IP domain, and LLC/MAC for connectivity in the Ethernet domain. When accessing services in the Ethernet domain, they will use the LLC/MAC connector and VLAN techniques and when accessing the IP domain, they will use the TCP/UDP/IP connector. The Ethernet and IP domains may co-exist on the same physical infrastructure, as the terminals described have the capacity to operate on either one or the other.
One of the main problems for the widespread use of broadband services is the need to connect up to them by means of a personal computer with an operating system, a solution too complex for the majority of potential users of the service, as they do not understand its operation nor are they capable of maintaining it properly. To this are added the high cost of the system and its rapid obsolescence, which means that the investment in computer equipment has a short period of life. It is unnecessary to describe the severe problems of security due to viruses and attacks of all kinds that arrive over the Internet, in the face of which the average user feels impotent and which sooner or later end up causing him problems, or the difficulties entailed in the management of the back-up copies of the information stored in the computer. All this is a task for professionals, and a complete solution is provided to this with the terminal that is proposed in this invention. First of all, through not having an operating system, the possible attacks from the network are minimised through being connected to the Ethernet domain controlled by the service supplier, which represents a protected area. As the local network is extended to the service supplier, he will be the one to install and maintain the different servers: applications, data, e-mail, names and addresses, audio, video, etc. With this system, we resolve the problem of software licenses, as the user pays for the service and the supplier takes care of paying for the respective licenses. Something similar happens in the case of audio and video, as the users will pay for the number of accesses to the contents. With these new services, the telecommunications operators may offset the loss of revenue they have been experiencing because of the telephone bill, due in a large extent to the expansion in the use of voice on packets.
If the end user so wishes, he will be able to have servers at his installation, the traffic of these being restricted to his segment of network, through being connected to the services supplier with a device that filters the traffic to the access network. This would be applicable from a small domestic network right up to a super-computer with thousands of parallel processors.
Through having to initiate only a small-sized program, the starting of the terminal is practically immediate. In case of problems, you only have to switch off and on, as the browser program and the file handler are in a non-volatile memory. For the extreme case of an irreparable failure occurring in these programs, the terminal will be endowed with the mechanisms needed to carry out an initial loading from the applications servers of the services supplier, who will also be the one responsible for installing the corresponding updates. A solution could be that every time the terminal is started, a connection is set up with the applications server, which will send it the necessary updates or the complete program if so requested by the user.